This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Causes of knee OA are unknown, but it is likely that biomechanical factors contribute to abnormal loading on the affected cartilage and bone. Effective non-surgical interventions are limited and may include strengthening, exercise and use of a cane or orthotic, but muscle activity may be the most significant modifiable factor. The proposed study is designed to investigate muscle forces and coordination strategies during gait in individuals with age-related osteoarthritis of the knee. This will be done thought a combination of MRI, gait analysis, electromyography, and biomechanical modeling and simulation. This project will build upon the clinical foundation projected by project #4, which takes a clinical approach to explore the progression of OA following TKA. Dr. Buchanan will serve as scientific mentor and Dr. Snyder-Mackler will be career mentor.